﻿#define  _CRT_SECURE_NO_WARNINGS
#include "snake.h"
//检测蛇是否撞墙
void KillByWall(pSnake ps)
{
	if (ps->_pSnake->x == 0 || ps->_pSnake->x == 56 ||
		ps->_pSnake->y == 0 || ps->_pSnake->y == 26)
	{
		ps->_status = KTLL_BY_WALL;
	}
}
//检测蛇是否撞到自己
void KillBySelf(pSnake ps)
{
	pSnakeNode cur = ps->_pSnake->next;
	while (cur)
	{
		if (cur->x == ps->_pSnake->x && cur->y == ps->_pSnake->y)
		{
			ps->_status = KILL_BY_SELF;
			break;
		}
		cur = cur->next;
	}
}
//检测下一个坐标处是否是食物
int NextIsFood(pSnakeNode pn, pSnake ps)
{
	return ps->_pFood->x == pn->x && ps->_pFood->y == pn->y;
}
//下一个位置不是食物 
void NoFood(pSnakeNode pn, pSnake ps)
{
	//头插法
	pn->next = ps->_pSnake;
	ps->_pSnake = pn;

	pSnakeNode cur = ps->_pSnake;
	while (cur->next->next != NULL)
	{
		SetPos(cur->x,cur->y);
		wprintf(L"%lc", BODY);
		cur = cur->next;
	}
	//此时cur为新蛇的最后一个节点
	SetPos(cur->next->x,cur->next->y);
	printf("  ");
	//释放旧蛇的最后一个节点
	free(cur->next);
	cur->next = NULL;
}
//下一个位置是食物，吃掉食物
void EatFood(pSnakeNode pn, pSnake ps)
{
	//头插法，把食物节点挂上去
	ps->_pFood->next = ps->_pSnake;
	ps->_pSnake = ps->_pFood;

	//释放下一个位置的节点
	free(pn);
	pn = NULL;

	//打印蛇
	pSnakeNode cur = ps->_pSnake;
	while (cur)
	{
		SetPos(cur->x,cur->y);
		wprintf(L"%lc",BODY);
		cur = cur->next;
	}
	ps->_score += ps->_food_weight;

	//重新创建一个食物
	CreateFood(ps);
}
//贪吃蛇走一步
void SnakeMove(pSnake ps)
{
	//创建一个节点，表示蛇即将到的下一个节点
	pSnakeNode pNextNode = (pSnakeNode)malloc(sizeof(SnakeNode));
	if (pNextNode == NULL)
	{
		perror("SnakeMove(): malloc fail!");
		return;
	}
	//首先确定方向
	switch (ps->_dir)
	{
	case UP:
		pNextNode->x = ps->_pSnake->x;
		pNextNode->y = ps->_pSnake->y - 1;
		break;
	case DOWN:
		pNextNode->x = ps->_pSnake->x;
		pNextNode->y = ps->_pSnake->y + 1;
		break;
	case LEFT:
		pNextNode->x = ps->_pSnake->x - 2;
		pNextNode->y = ps->_pSnake->y;
		break;
	case RIGHT:
		pNextNode->x = ps->_pSnake->x + 2;
		pNextNode->y = ps->_pSnake->y;
		break;
	}
	//检测下一个坐标处是否是食物
	if (NextIsFood(pNextNode,ps))
	{
		//下一个位置是食物，吃掉食物
		EatFood(pNextNode, ps);
		pNextNode = NULL;
	}
	else
	{
		//不是食物
		NoFood(pNextNode, ps);
	}
	//检测蛇是否撞墙
	KillByWall(ps);
	//检测蛇是否撞到自己
	KillBySelf(ps);
}


//打印帮助信息
void PrintHelpInfo()
{
	SetPos(64,12);
	wprintf(L"%ls",L"不能穿墙，不能咬到自己");
	SetPos(64, 13);
	wprintf(L"%ls", L"用 ↑. ↓. ←. → 来控制蛇的移动");
	SetPos(64, 14);
	wprintf(L"%ls", L"按F3加速，F4减速");
	SetPos(64, 15);
	wprintf(L"%ls", L"按ESC退出游戏，按空格暂停游戏");
	SetPos(64, 16);
	wprintf(L"%ls", L"BMW i8制作");
}

#define KEY_PRESS(vk) ((GetAsyncKeyState(vk)&1)?1:0)
//暂停
void Pause()
{
	while (1)
	{
		Sleep(200);
		if (KEY_PRESS(VK_SPACE))
		{
			break;
		}
	}
}
//游戏运行的逻辑
void GameRun(pSnake ps)
{
	//打印帮助信息
	PrintHelpInfo();
	//检测按键情况
	do
	{
		//打印总分数和食物的分值
		SetPos(64, 8);
		printf("总分数：%d\n",ps->_score);
		SetPos(64, 9);
		printf("当前食物的分数%2d\n",ps->_food_weight);

		if (KEY_PRESS(VK_UP) && ps->_dir != DOWN)
		{
			ps->_dir = UP;
		}
		else if (KEY_PRESS(VK_DOWN) && ps->_dir != UP)
		{
			ps->_dir = DOWN;
		}
		else if (KEY_PRESS(VK_LEFT) && ps->_dir != RIGHT)
		{
			ps->_dir = LEFT;
		}
		else if (KEY_PRESS(VK_RIGHT) && ps->_dir != LEFT)
		{
			ps->_dir = RIGHT;
		}
		else if (KEY_PRESS(VK_SPACE))
		{
			//暂停
			Pause();
		}
		else if (KEY_PRESS(VK_ESCAPE))
		{
			//退出
			ps->_status = END_NORMAL;
		}
		else if (KEY_PRESS(VK_F3))
		{
			//加速
			if (ps->_sleep_time > 80)
			{
				ps->_sleep_time -= 30;
				ps->_food_weight += 2;
			}
		}
		else if (KEY_PRESS(VK_F4))
		{
			//减速
			if (ps->_food_weight > 2)
			{
				ps->_sleep_time += 30;
				ps->_food_weight -= 2;
			}
		}
		//贪吃蛇走一步
		SnakeMove(ps);//蛇走一步的过程
		Sleep(ps->_sleep_time);
	} while (ps->_status == OK);
	
}

//4.创建食物
void CreateFood(pSnake ps)
{
	//随机生成食物的坐标
	int x = 0;
	int y = 0;
	//保证生成的x是2的倍数
	//x的范围是2~54
	//y的范围是1~25
again:
	do
	{
		x = rand() % 53 + 2;
		y = rand() % 25 + 1;
	} while (x % 2 != 0);
	//x和y的坐标不能和蛇的身体冲突
	pSnakeNode cur = ps->_pSnake;
	while (cur)
	{
		if (x == cur->x && y == cur->y)
		{
			goto again;
		}
		cur = cur->next;
	}

	//创建食物的节点
	pSnakeNode pFood = (pSnakeNode)malloc(sizeof(SnakeNode));
	if (pFood == NULL)
	{
		perror("CreateFood():malloc fail!");
		return;
	}

	pFood->x = x;
	pFood->y = y;
	pFood->next = NULL;

	SetPos(x,y);//定位位置
	wprintf(L"%lc",FOOD);
	ps->_pFood = pFood;
	
}
//初始化蛇身
void InitSnake(pSnake ps)
{
	int i = 0;
	pSnakeNode cur = NULL;
	for (i = 0; i < 5; i++)
	{
		cur = (pSnakeNode)malloc(sizeof(SnakeNode));
		if (cur == NULL)
		{
			perror("InitSnake():malloc fail!");
			return;
		}
		//空间申请成功
		cur->next = NULL;
		cur->x = POS_X + 2 * i;
		cur->y = POS_Y;

		//头插法插入链表
		if (ps->_pSnake == NULL)
		{
			//说明是一个空链表
			ps->_pSnake = cur;
		}
		else
		{
			cur->next = ps->_pSnake;
			ps->_pSnake = cur;
		}
	}
	//打印蛇
	cur = ps->_pSnake;
	while (cur)
	{
		SetPos(cur->x, cur->y);
		wprintf(L"%lc", BODY);
		cur = cur->next;
	}
	//设置贪吃蛇的属性
	ps->_dir = RIGHT;//默认向右
	ps->_score = 0;
	ps->_food_weight = 10;
	ps->_sleep_time = 200;//单位是毫秒
	ps->_status = OK;
	
}
//创建地图
void CreateMap()
{
	//上
	int i = 0;
	for (i = 0; i < 29; i++)
	{
		wprintf(L"%lc", WALL);
	}
	//下
	SetPos(0,26);
	for (i = 0; i < 29; i++)
	{
		wprintf(L"%lc", WALL);
	}
	//左
	for (i = 1; i <= 25; i++)
	{
		SetPos(0, i);
		wprintf(L"%lc", WALL);
	}
	//右
	for (i = 1; i <= 25; i++)
	{
		SetPos(56, i);
		wprintf(L"%lc", WALL);
	}
	
}
//定位光标位置
void SetPos(short x, short y)
{
	//获得标准输出设备的句柄
	HANDLE houtput = NULL;
	houtput = GetStdHandle(STD_OUTPUT_HANDLE);
	//定位光标的位置
	COORD pos = { x,y };
	SetConsoleCursorPosition(houtput,pos);
}
void WelcomeToGame()
{
	//定位光标位置
	SetPos(40,14);
	wprintf(L"欢迎来到贪吃蛇小游戏\n");
	SetPos(42,20);
	system("pause");
	//清屏
	system("cls");
	//进入下一个界面
	SetPos(25, 14);
	wprintf(L"用 ↑. ↓. ←. → 来控制蛇的移动，按F3加速，F4减速\n");
	SetPos(25, 15);
	wprintf(L"加速能够得到更高的分数\n");
	SetPos(42, 20);
	system("pause");
	system("cls");

}
void GameStart(pSnake ps)
{
	//0.先设置窗口的大小，再光标隐藏
	system("mode con cols=100 lines=30");
	system("title 贪吃蛇");
	HANDLE houtput = GetStdHandle(STD_OUTPUT_HANDLE);
	CONSOLE_CURSOR_INFO CurSorInfo;
	GetConsoleCursorInfo(houtput,&CurSorInfo);//获取控制台光标信息
	CurSorInfo.bVisible = false;//隐藏控制台光标
	SetConsoleCursorInfo(houtput,&CurSorInfo);//设置控制台光标状态
	//1.打印欢迎界面和功能介绍
	WelcomeToGame();
	//2.绘制地图
	CreateMap();
	//3.创建蛇
	InitSnake(ps);
	//4.创建食物
	CreateFood(ps);
}
// 结束游戏 - 善后工作（如销毁节点）
void GameEnd(pSnake ps)
{
	SetPos(24, 12);
	switch (ps->_status)
	{
	case END_NORMAL:
		printf("您主动结束游戏\n");
		break;
	case KTLL_BY_WALL:
		printf("您撞到墙上，游戏结束\n");
		break;
	case KILL_BY_SELF:
		printf("您撞到了自己，游戏结束\n");
		break;

	}

	//释放蛇身的链表
	pSnakeNode cur = ps->_pSnake;
	while (cur)
	{
		pSnakeNode del = cur;
		cur = cur->next;
		free(del);
	}
}